diff options
Diffstat (limited to 'fs/reiserfs/tail_conversion.c')
| -rw-r--r-- | fs/reiserfs/tail_conversion.c | 151 |
1 files changed, 94 insertions, 57 deletions
diff --git a/fs/reiserfs/tail_conversion.c b/fs/reiserfs/tail_conversion.c index fc1981d858dc..f41e19b4bb42 100644 --- a/fs/reiserfs/tail_conversion.c +++ b/fs/reiserfs/tail_conversion.c @@ -1,5 +1,6 @@ /* - * Copyright 1999 Hans Reiser, see reiserfs/README for licensing and copyright details + * Copyright 1999 Hans Reiser, see reiserfs/README for licensing and copyright + * details */ #include <linux/time.h> @@ -7,13 +8,19 @@ #include <linux/buffer_head.h> #include "reiserfs.h" -/* access to tail : when one is going to read tail it must make sure, that is not running. - direct2indirect and indirect2direct can not run concurrently */ +/* + * access to tail : when one is going to read tail it must make sure, that is + * not running. direct2indirect and indirect2direct can not run concurrently + */ -/* Converts direct items to an unformatted node. Panics if file has no - tail. -ENOSPC if no disk space for conversion */ -/* path points to first direct item of the file regarless of how many of - them are there */ +/* + * Converts direct items to an unformatted node. Panics if file has no + * tail. -ENOSPC if no disk space for conversion + */ +/* + * path points to first direct item of the file regardless of how many of + * them are there + */ int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, struct treepath *path, struct buffer_head *unbh, loff_t tail_offset) @@ -22,14 +29,20 @@ int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, struct buffer_head *up_to_date_bh; struct item_head *p_le_ih = tp_item_head(path); unsigned long total_tail = 0; - struct cpu_key end_key; /* Key to search for the last byte of the - converted item. */ - struct item_head ind_ih; /* new indirect item to be inserted or - key of unfm pointer to be pasted */ - int blk_size, retval; /* returned value for reiserfs_insert_item and clones */ - unp_t unfm_ptr; /* Handle on an unformatted node - that will be inserted in the - tree. */ + + /* Key to search for the last byte of the converted item. */ + struct cpu_key end_key; + + /* + * new indirect item to be inserted or key + * of unfm pointer to be pasted + */ + struct item_head ind_ih; + int blk_size; + /* returned value for reiserfs_insert_item and clones */ + int retval; + /* Handle on an unformatted node that will be inserted in the tree. */ + unp_t unfm_ptr; BUG_ON(!th->t_trans_id); @@ -37,8 +50,10 @@ int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, blk_size = sb->s_blocksize; - /* and key to search for append or insert pointer to the new - unformatted node. */ + /* + * and key to search for append or insert pointer to the new + * unformatted node. + */ copy_item_head(&ind_ih, p_le_ih); set_le_ih_k_offset(&ind_ih, tail_offset); set_le_ih_k_type(&ind_ih, TYPE_INDIRECT); @@ -76,20 +91,26 @@ int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, if (retval) { return retval; } - // note: from here there are two keys which have matching first - // three key components. They only differ by the fourth one. + /* + * note: from here there are two keys which have matching first + * three key components. They only differ by the fourth one. + */ /* Set the key to search for the direct items of the file */ make_cpu_key(&end_key, inode, max_reiserfs_offset(inode), TYPE_DIRECT, 4); - /* Move bytes from the direct items to the new unformatted node - and delete them. */ + /* + * Move bytes from the direct items to the new unformatted node + * and delete them. + */ while (1) { int tail_size; - /* end_key.k_offset is set so, that we will always have found - last item of the file */ + /* + * end_key.k_offset is set so, that we will always have found + * last item of the file + */ if (search_for_position_by_key(sb, &end_key, path) == POSITION_FOUND) reiserfs_panic(sb, "PAP-14050", @@ -101,11 +122,12 @@ int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, tail_size = (le_ih_k_offset(p_le_ih) & (blk_size - 1)) + ih_item_len(p_le_ih) - 1; - /* we only send the unbh pointer if the buffer is not up to date. - ** this avoids overwriting good data from writepage() with old data - ** from the disk or buffer cache - ** Special case: unbh->b_page will be NULL if we are coming through - ** DIRECT_IO handler here. + /* + * we only send the unbh pointer if the buffer is not + * up to date. this avoids overwriting good data from + * writepage() with old data from the disk or buffer cache + * Special case: unbh->b_page will be NULL if we are coming + * through DIRECT_IO handler here. */ if (!unbh->b_page || buffer_uptodate(unbh) || PageUptodate(unbh->b_page)) { @@ -117,13 +139,15 @@ int direct2indirect(struct reiserfs_transaction_handle *th, struct inode *inode, up_to_date_bh); total_tail += retval; + + /* done: file does not have direct items anymore */ if (tail_size == retval) - // done: file does not have direct items anymore break; } - /* if we've copied bytes from disk into the page, we need to zero - ** out the unused part of the block (it was not up to date before) + /* + * if we've copied bytes from disk into the page, we need to zero + * out the unused part of the block (it was not up to date before) */ if (up_to_date_bh) { unsigned pgoff = @@ -146,9 +170,11 @@ void reiserfs_unmap_buffer(struct buffer_head *bh) BUG(); } clear_buffer_dirty(bh); - /* Remove the buffer from whatever list it belongs to. We are mostly - interested in removing it from per-sb j_dirty_buffers list, to avoid - BUG() on attempt to write not mapped buffer */ + /* + * Remove the buffer from whatever list it belongs to. We are mostly + * interested in removing it from per-sb j_dirty_buffers list, to avoid + * BUG() on attempt to write not mapped buffer + */ if ((!list_empty(&bh->b_assoc_buffers) || bh->b_private) && bh->b_page) { struct inode *inode = bh->b_page->mapping->host; struct reiserfs_journal *j = SB_JOURNAL(inode->i_sb); @@ -164,12 +190,14 @@ void reiserfs_unmap_buffer(struct buffer_head *bh) unlock_buffer(bh); } -/* this first locks inode (neither reads nor sync are permitted), - reads tail through page cache, insert direct item. When direct item - inserted successfully inode is left locked. Return value is always - what we expect from it (number of cut bytes). But when tail remains - in the unformatted node, we set mode to SKIP_BALANCING and unlock - inode */ +/* + * this first locks inode (neither reads nor sync are permitted), + * reads tail through page cache, insert direct item. When direct item + * inserted successfully inode is left locked. Return value is always + * what we expect from it (number of cut bytes). But when tail remains + * in the unformatted node, we set mode to SKIP_BALANCING and unlock + * inode + */ int indirect2direct(struct reiserfs_transaction_handle *th, struct inode *inode, struct page *page, struct treepath *path, /* path to the indirect item. */ @@ -207,9 +235,11 @@ int indirect2direct(struct reiserfs_transaction_handle *th, 1) * sb->s_blocksize; pos1 = pos; - // we are protected by i_mutex. The tail can not disapper, not - // append can be done either - // we are in truncate or packing tail in file_release + /* + * we are protected by i_mutex. The tail can not disapper, not + * append can be done either + * we are in truncate or packing tail in file_release + */ tail = (char *)kmap(page); /* this can schedule */ @@ -236,9 +266,10 @@ int indirect2direct(struct reiserfs_transaction_handle *th, pos1 + 1, TYPE_DIRECT, round_tail_len, 0xffff /*ih_free_space */ ); - /* we want a pointer to the first byte of the tail in the page. - ** the page was locked and this part of the page was up to date when - ** indirect2direct was called, so we know the bytes are still valid + /* + * we want a pointer to the first byte of the tail in the page. + * the page was locked and this part of the page was up to date when + * indirect2direct was called, so we know the bytes are still valid */ tail = tail + (pos & (PAGE_CACHE_SIZE - 1)); @@ -250,12 +281,14 @@ int indirect2direct(struct reiserfs_transaction_handle *th, /* Insert tail as new direct item in the tree */ if (reiserfs_insert_item(th, path, &key, &s_ih, inode, tail ? tail : NULL) < 0) { - /* No disk memory. So we can not convert last unformatted node - to the direct item. In this case we used to adjust - indirect items's ih_free_space. Now ih_free_space is not - used, it would be ideal to write zeros to corresponding - unformatted node. For now i_size is considered as guard for - going out of file size */ + /* + * No disk memory. So we can not convert last unformatted node + * to the direct item. In this case we used to adjust + * indirect items's ih_free_space. Now ih_free_space is not + * used, it would be ideal to write zeros to corresponding + * unformatted node. For now i_size is considered as guard for + * going out of file size + */ kunmap(page); return block_size - round_tail_len; } @@ -264,12 +297,16 @@ int indirect2direct(struct reiserfs_transaction_handle *th, /* make sure to get the i_blocks changes from reiserfs_insert_item */ reiserfs_update_sd(th, inode); - // note: we have now the same as in above direct2indirect - // conversion: there are two keys which have matching first three - // key components. They only differ by the fouhth one. + /* + * note: we have now the same as in above direct2indirect + * conversion: there are two keys which have matching first three + * key components. They only differ by the fourth one. + */ - /* We have inserted new direct item and must remove last - unformatted node. */ + /* + * We have inserted new direct item and must remove last + * unformatted node. + */ *mode = M_CUT; /* we store position of first direct item in the in-core inode */ |